Windows 7 - Bootcamp - From USB - Possible?

Hey guys i am new here and also sorta new to MAC...

I just bought a new MBP 2011 and want to bootcamp it and install WIN on a partion of the drive... As i opened the bootcamp ***. i noticed i wasn't able to use option one, the one option allowing me to boot WIN 7 from an USB..

My first question to you pro guys is, is it possible to install WIN 7.iso from an usb on a new MBP?? // Using macs bootcamp or is it possible with some other programs?

I tried changing the info.plist that you find in bootcamp if you open package contents to try and unblock the option and changing:

<key>USBBootSupportedModels</key>
<array>
<string>IM130</string>
<string>MM50</string>
<string>MP60</string>
<string>MB80</string>
<string>MBP90</string>
<string>MBA40</string>

I added this since it should be my mac name here. I have also tried writing MB instead of MBP

<string>MBP81</string>

but this did not help and the option remained grayed out..

Do i really have to and buy DVDs to burn the iso file to? OR?

Follow the procedure give here. Although the article talks about installing on a MacBook Air, the routine should be the same.